Although the study of resource subsidies has emerged as a key topic in both ecosystem and food web ecology, the dialogue over their role has been limited by separate approaches that emphasize either subsidy quantity or quality. Considering quantity and quality together may provide a simple, but previously unexplored, framework for identifying the mechanisms that govern the importance of subsidies for recipient food webs and ecosystems. Using a literature review of >90 studies of open‐water metabolism in lakes and streams, we show that high‐flux, low‐quality subsidies can drive freshwater ecosystem dynamics. Because most of these ecosystems are net heterotrophic, allochthonous inputs must subsidize respiration. Second, using a literature review of subsidy quality and use, we demonstrate that animals select for high‐quality food resources in proportions greater than would be predicted based on food quantity, and regardless of allochthonous or autochthonous origin. This finding suggests that low‐flux, high‐quality subsidies may be selected for by animals, and in turn may disproportionately affect food web and ecosystem processes (e.g., animal production, trophic energy or organic matter flow, trophic cascades). We then synthesize and review approaches that evaluate the role of subsidies and explicitly merge ecosystem and food web perspectives by placing food web measurements in the context of ecosystem budgets, by comparing trophic and ecosystem production and fluxes, and by constructing flow food webs. These tools can and should be used to address future questions about subsidies, such as the relative importance of subsidies to different trophic levels and how subsidies may maintain or disrupt ecosystem stability and food web interactions.
The issues facing academic mothers have been discussed for decades. Coronavirus Disease 2019 (COVID-19) is further exposing these inequalities as womxn scientists who are parenting while also engaging in a combination of academic related duties are falling behind. These inequities can be solved by investing strategically in solutions. Here we describe strategies that would ensure a more equitable academy for working mothers now and in the future. While the data are clear that mothers are being disproportionately impacted by COVID-19, many groups could benefit from these strategies. Rather than rebuilding what we once knew, let us be the architects of a new world.
We estimated past and future hydrographs and patterns of ecosystem metabolism in a fifth‐order river of the western United States, where water use and climate change are both expected to alter hydrology in the immediate future. We first reconstructed the unregulated hydrograph to estimate how the current hydrograph has been altered. Due to consumptive use, 95% as irrigation, current discharge during summer (July–September) was 70% lower than would occur if the river was unregulated. We then predicted a future hydrograph including effects of consumptive use and climate change; the magnitude of flow changes were minor under this regime relative to those already manifested by consumptive uses. We used time‐series regression and a six‐year continuous record of open‐water metabolism to demonstrate that, under the current hydrologic regime, gross primary production (GPP) was dependent on both water temperature and flow and that ecosystem respiration (ER) was most dependent on temperature. Monte Carlo simulations under the three hydrologic regimes and three temperature scenarios (current, +2°C, +4°C) suggested that flow, but not temperature, may have profound effects on the magnitude of metabolism. Linking temporally detailed analyses of ecological function and hydrology may lead to better understanding and management of changes due to basin‐scale water use and/or global‐scale climate change.
29 October 2021 in Limnology and Oceanography Letters
N2 fixation is a major component of the global N cycle and has been extensively studied in open‐ocean and terrestrial ecosystems. Yet rates and ecological dynamics remain virtually unknown for the inland and coastal aquatic ecosystems (lakes, wetlands, rivers, streams, and estuaries) that connect terrestrial and marine biomes. This is due to the diversity of these habitats as well as the traditional paradigm that N2 fixation rates were low to nonexistent, and therefore not important, in these ecosystems. We identify three major research themes to advance understanding of aquatic N2 fixation: (1) the biological diversity of diazotrophs and variability of N2 fixation rates, (2) the ecological stoichiometry of N2 fixation, and (3) the upscaling of N2 fixation rates from genes to ecosystems. Coordinating research across these areas will advance limnology and oceanography by fully integrating N2 fixation into ecological dynamics of aquatic ecosystems from local to global scales.